Pneumatic suspension system

ABSTRACT

The invention relates to a pneumatic suspension system ( 1 ) comprising at least the following parts: pneumatic suspension bellows ( 4 ) made of an elastomer material encompassing a volume-variable air chamber ( 5 ); a pneumatic suspension lid ( 7 ) to which one end of the pneumatic suspension bellows is fixed by means of a clamping ring ( 10 ) or the like; a pneumatic suspension piston ( 3 ) to which the other end of the pneumatic suspension bellows ( 4 ) is also fixed by means of a clamping ring ( 10 ) or the like and on whose outer wall the pneumatic suspension bellows can roll ( 6 ) by forming a rolling contour; a wheel guide element ( 9 ); a hinge ( 8 ) serving as steering means in relation to the wheel guide element ( 9 ) and a body ( 2 ), wherein the pneumatic suspension parts are disposed in such a way that only one hinge ( 8 ) is provided as a steering element in relation to the wheel guide element ( 9 ) inside the pneumatic suspension system ( 1 ) without requiring any centric restricted guidance. Several advantageous embodiments are disclosed.

CROSS REFERENCE TO RELATED APPLICATIONS

Applicant claims priority under 35 U.S.C. §119 of German Application No.198 55 814.7 filed Dec. 3, 1998. Applicant also claims priority under 35U.S.C. §120 of PCT/DE99/03503 filed Nov. 3, 1999. The internationalapplication under PCT article 21(2) was not published in English.

BACKGROUND OF THE INVENTION DESCRIPTION

1. Field of the Invention

The invention relates to a pneumatic suspension system comprising atleast the following pneumatic suspension system components,specifically:

a pneumatic suspension bellows made of an elastomer material enclosing avolume-variable air chamber;

a pneumatic suspension lid to which one end of the pneumatic suspensionbellows is fixed by means of a clamping ring or the like;

a pneumatic suspension piston to which the other end of the pneumaticsuspension bellows is fixed by means of a clamping ring or the like aswell and on whose outer wall the pneumatic suspension bellows can rolloff, forming a rolling contour;

a wheel guide element;

a hinge serving as the steering means in relation to the wheel guideelement; as well as

a body.

2. The Prior Art

With pneumatic suspension systems without a damper disposed on theinside, the pneumatic suspension lid is secured on the body and thepneumatic suspension piston on a wheel guide element. In the presence ofspring action, the piston is then moving in relation to the lidaccording to the wheel guide kinematics, whereby it is not assured thatthe pneumatic suspension bellows rolls off on the piston in a symmetricmanner.

Now a pneumatic suspension system of this type is disclosed in laid-openpatent specification DE 197 04 433 A1, where the problem of relativemovements between the components of the pneumatic suspension system issolved by means of an inner guide in the form of centric forcedguidance. In this system, a hinge is in connection with the body andanother hinge with the wheel guide element. The two hinges are connectedwith each other by means of the inner guide, which preferably is aguiding cylinder-and-push rod device. Since the inner guide is notintended to assume any damping properties, the pneumatic suspensionsystem has to be separately provided with a damper. The frictionoccurring on the inner guide in the presence of spring action, inparticular with maximum spring action to the limit of suspension, thenleads to a deterioration of the pneumatic suspension system in relationto the vehicle.

Now, the problem of the invention is to provide a pneumatic suspensionsystem without a damper disposed on the inside, in which system thewheel guide kinematics in relation to symmetric roll-off of thepneumatic suspension bellows is realized without inside guide elementsinfluencing the comfort.

SUMMARY OF THE INVENTION

The problem is solved by the invention in that the components of thepneumatic suspension system are arranged in a such a way that only onesingle hinge is present within the pneumatic suspension system as thesteering means in relation to the wheel guide element, with omission ofcentric forced guidance.

Advantageous design variations are explained in the following in greaterdetail.

Variation A

According to this variation, which within the framework of the conceptas defined by the invention contains a particularly advantageousembodiment of the invention, the pneumatic suspension piston as theupper component is tied to the body, whereby the rolling fold of thepneumatic suspension bellows is bulging upwards. The pneumaticsuspension lid as the lower component is connected with the hinge withinthe bottom of the lid, specifically with centric tie-up of the pneumaticsuspension lid to the wheel guide element by means of the hinge.

Variation B

According to this variation, the pneumatic suspension lid as the uppercomponent is tied to the body, whereas the pneumatic suspension pistonas the lower component is connected with the hinge, whereby the hinge islocated within the piston chamber and/or air chamber, specifically withcentric tie-up of the pneumatic suspension piston to the wheel guideelement by means of a rod extending within the piston.

Variation C

According to this variation, the pneumatic suspension lid as the uppercomponent is tied to the body, whereas the pneumatic suspension pistonas the lower component is connected with the hinge within the bottom ofthe piston, specifically with centric tie-up of the pneumatic suspensionpiston to the wheel guide element by means of the hinge. The angle ofmovement of the hinge is reduced in this connection in such a way thatthe piston is prevented from tilting in the presence of kinematic springaction.

Variation D

According to this variation, the pneumatic suspension lid as the uppercomponent is connected with the hinge, specifically with centric tie-upof the pneumatic suspension lid to the body by means of the hinge. Thepneumatic suspension piston as the lower component is centrically tiedto the wheel guide element within the bottom of the piston.

Further advantageous design variations are discussed below, wherebyparticularly in conjunction with variation A, the pneumatic suspensionsystem is additionally equipped with a protective bellows and/or asupporting ring.

Furthermore, it is advantageous in connection with variation A if thehinge is designed in the form of a bush-like component comprising atubular core, a cushion made of elastomer material, and an outer sleeve.

The pneumatic suspension bellows is provided with a reinforcing insertin most cases (DE 36 43 073 A1).

Furthermore, the air chamber may be connectable via a channel with anadditional air volume for increasing the comfort of the pneumaticsuspension system (DE 197 04 433 A1).

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in the following with the help of exemplifiedembodiments and by reference to schematic drawings, in which:

FIG. 1 shows a pneumatic suspension system according to variation A.

FIG. 2 shows a pneumatic suspension system according to variation B.

FIG. 3 shows a pneumatic suspension system according to variation C.

FIG. 4 shows a pneumatic suspension system according to variation D.

FIG. 5 shows another pneumatic suspension system according to variationA.

The following list of reference numerals and symbols is applicable inconnection with said figures:

1, 1′, 1″, 1′″, 1″″ Pneumatic suspension system 2, 2′, 2″, 2′″ Body 3,3′, 3″, 3′″ Pneumatic suspension piston (roll-off piston) 4, 4′, 4″,4′″. 4″″ Pneumatic suspension bellows 5, 5′, 5″, 5′″ Air chamber 6, 6′,6″, 6′″ Rolling fold 7, 7′, 7″, 7′″, 7″″ Pneumatic suspension lid 8, 8′,8″, 8′″ Hinge 9, 9′, 9″, 9′″ Wheel guide element 10 Clamping ring 11Outer guide 12 Protective bellows 13 Piston chamber 14 Rod 15 Bush-likecomponent 16 Core 17 Cushion made of elastomer material 18 Outer sleeve19 Supporting ring

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a pneumatic suspension system 1 in which the pneumaticsuspension piston 3 as the upper component is tied to the body 2,whereby the rolling fold 6 of the pneumatic suspension bellows 4 isbulging upwards. In the present embodiment, the pneumatic suspensionbellows made of elastomer material encloses an air chamber 5 with avariable volume.

The pneumatic suspension lid 7 as the lower component is connectedwithin the bottom of the lid with the hinge 8 (ball joint), specificallywith centric tie-up (i.e. with respect to the center plane X) of thepneumatic suspension lid to the wheel guide element 9 by means of thehinge.

Furthermore, the pneumatic suspension system 1 is equipped with aprotective bellows 12 made of elastomer material or TPE (thermoplasticelastomer), with the lower part of the protective bellows being securedon the outer guide 11. It may be fastened there in a rigid or a flexiblemanner.

In the pneumatic suspension system 1′ according to FIG. 2, the pneumaticsuspension lid 7′ as the upper component may be tied to the body 2′.

The pneumatic suspension piston 3′ as the lower component is connectedwith the hinge 8′ (ball joint), whereby the hinge is located within thepiston chamber 13, also in the present case specifically with centrictie-up of the pneumatic suspension piston to the wheel guide element 9′by means of a rod 14 extending within the piston.

FIG. 3 shows a pneumatic suspension system 1″, in which, like in theexemplified embodiment according to FIG. 2, the pneumatic suspension lid7″ as the upper component is tied to the body 2″.

The pneumatic suspension piston 3″ as the lower component is connectedwithin the head of the piston with the hinge 8″ (ball joint), also inthe present embodiment specifically with centric tie-up of the pneumaticsuspension piston to the wheel guide element 9″ by means of the hinge.

In the pneumatic suspension system 1′″ according to FIG. 4, thepneumatic suspension lid 7′″ as the upper component is connected withthe hinge 8′″ (ball joint), specifically with centric tie-up (i.e. withrespect to the center plane X) of the pneumatic suspension lid to thebody 2′″ by means of the hinge.

The pneumatic suspension piston 3′″ as the upper component iscentrically tied to the wheel guide element 9′″.

FIG. 5 shows a pneumatic suspension system 1″″ with the basic structureaccording to FIG. 1.

The pneumatic suspension lid 7″″ as the lower component is connectedwithin the bottom of the lid with the hinge. In the present embodiment,the hinge is realized in the form of a bush-like component or jacket 15comprising a core 16, a cushion 17 made of elastomer material, and anouter sleeve 18. The core itself is connected with the wheel guideelement.

The pneumatic suspension system 1″″ (in the present case without theouter guide) is equipped with a supporting ring 19 for the pneumaticsuspension bellows 4″″, namely in the location where the pneumaticsuspension bellows is secured on the pneumatic suspension lid by meansof the clamping ring 10.

In the present embodiment, the lower part of the protective bellows 12is secured on the supporting ring 19.

What is claimed is:
 1. A pneumatic suspension system for supporting abody comprising: (a) an upper component comprising a pneumaticsuspension piston adapted for mounting to the body; (b) a pneumaticsuspension bellows secured to said pneumatic suspension piston andforming an upwards rolling fold when said pneumatic suspension bellowsrolls off an outer surface of said pneumatic suspension piston; (c) alower component comprising a pneumatic suspension lid secured to one endof said pneumatic suspension bellows; (d) a single hinge disposedadjacent to and directly connected to said pneumatic suspension lid; (e)a wheel guide element connected to said hinge, a bottom portion of saidpneumatic suspension lid being centrally connected to said wheel guideelement by means of said hinge, said hinge serving as a steering meansin relation to the wheel guide element without requiring centric forcedguidance.
 2. The pneumatic suspension system according to claim 1,wherein the hinge is designed in the form of a ball joint, or a jacket,said jacket comprising a core, a cushion made of elastomeric material,and an outer sleeve.
 3. The pneumatic suspension system according toclaim 1, wherein the pneumatic suspension bellows is provided with anouter guide, whereby the outer guide is rigidly or flexibly secured onthe pneumatic suspension system.
 4. The pneumatic suspension systemaccording to claim 1, wherein said system is equipped with a protectivebellows made of an elastomeric material or a thermoplastic elastomer,said protective bellows being secured on the pneumatic suspensionbellows or on another pneumatic suspension component.
 5. The pneumaticsuspension system according to claim 1, wherein said system is equippedwith a supporting ring for the pneumatic suspension bellows.